I have a page that functions correctly but when i issue a deny user for the whole site it redirects me to the logon page which seems to work BUT the css is not working. Henc
Try removing the tilda (~) in your location's path attribute. If you look at the fiddler result, its a callback request for your css. so the unauthenticated request for the page is in turn making unauthenticated requests for resources (the css).
I generally try to place a styles directory at the root of the application, and then use a helper tool like T4MVC or my own helper methods to translate and avoid having to figure out the ../../ directory crawling.